Wheel bearings and wheel hubs are known to be highly loaded components for wheel suspensions on the chassis of a motor vehicle, which must withstand an extremely wide variety of loads in particular in utility motor vehicles. A long service-life and maintenance-free use of the wheel bearings and wheel hubs are decisive competitive advantages of such utility vehicles. In spite of the very long service-life and freedom from maintenance, a repair of defective bearings is often necessary and more cost-effective than a new replacement. To this end, wheel bearing units are offered as replacement parts in the aftermarket sector.
In wheel bearing units for utility motor vehicles, so-called insert tapered roller bearing units are primarily used.
A so-called insert bearing is also known from DE 10 2006 017 162 A1. The insert wheel bearing unit described in this instance is a replaceable unit which can be assembled without specific technical knowledge and without special tools using simple auxiliary tools available in repair workshops, without any special requirement in terms of cleanliness during assembly. The bearing unit comprises two tapered roller bearings, each having an outer ring and an inner ring, between which a row of tapered rollers is arranged in each case. The tapered roller bearings are arranged in a mirror-inverted manner with respect to each other in the wheel hub and fixed using a securing ring. During assembly, the individual wheel bearings are axially pressed into the wheel hub, a projection in the wheel hub acting as a stop in each case. Owing to axial insertion of a securing ring into corresponding grooves of the inner rings, the inner rings are connected to each other and the bearing is fixed.
A connection ring for holding together inner raceway portions of adjacent bearings is known from DE 694 09 511 T2. The connection ring has a high level of strength and enables simple assembly of two bearings, for example, to form a wheel bearing. The connection ring is produced from a resilient material and has two opposing rows of outwardly protruding resilient tongues, which rows extend at the periphery. Owing to the resilient tongues, the connection ring can be readily inserted into the inner raceway of a bearing. When the connection ring is in its end position, the tongues spring outwards in order to lock the ring at the location thereof. The inner raceway of the second bearing can then be pressed onto the exposed half of the connection ring until it is locked by the tongue of the second peripheral row. The outer rings are each introduced into the wheel hub from different sides as far as a stop. The inner rings of the bearings strike each other with the end faces thereof, that is to say, the inner rings must be produced with a larger width than the outer rings. This means a great material use of expensive roller bearing steel.
There is known from DE 10 2004 018 901 B3 a roller bearing subassembly which can be mounted on a frustoconical hub. The roller bearing subassembly comprises an outer ring which is constructed in one piece and an inner ring which is constructed in at least two pieces. The roller members are tapered rollers. At the location at which the two inner rings are in mutual abutment in accordance with provisions, both inner rings are constructed so as to be able to engage one in the other in an axial direction. To this end, each of the inner rings is provided in an end region towards the said side with an annular groove which is constructed in an axial direction as an undercut so as to co-operate with an annular region located upstream of the groove in the direction towards the said end. The mutually facing covering faces of the annular regions are provided with a thread. The inner rings can thereby be screwed securely one inside the other during first assembly. In the assembled state, the threads are released from each other. The connection is releasable and can be loaded in an axial direction. The total width of the inner and outer rings must correspond to the total width of the bearing unit.
DE 198 58 973 C1 describes a multi-row roller bearing having at least two separate inner and/or outer rings. The two axially adjacent inner or outer rings are connected to each other in the region of the common assembly joint by means of a connection element. In an axial cylindrical portion of the separation joint, there is provided a recess in which a wire-like connection element is inserted.
From DE 10 2006 026 443 A1, there is known a roller bearing having two inner rings and a sealing arrangement for sealing the separation joint between the inner rings.
From DE 199 61 712 B4 there is known a multi-row roller bearing having at least two separate inner and/or outer rings which are directly connected to each other. The inner rings each have an axially extended region having a recess, the outer contour of one inner ring engaging in the recess of the other inner ring. This bearing has a single non-divided outer ring. This also involves high material costs for the expensive roller bearing steel.
The known insert bearing units, depending on the total width of the bearing unit, have long and consequently expensive inner rings. The bearing units having a single-piece outer ring are expensive to produce with a high use of roller bearing material.